• Title/Summary/Keyword: useful material

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Useful Lifetime Evaluation of Rubber Component for Elevator Cabin (승강기용 방진고무부품 특성 및 사용수명 평가)

  • Woo, Chang-Su;Park, Hyun-Sung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.576-580
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    • 2008
  • Rubber material properties and useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the evaluation of characteristics and useful life prediction of rubber component for elevator cabin were experimentally investigated. The material test and accelerated heat-aging test were carried. Rubber material constants were obtained by curve fittings of simple tension, pure shear and bi-axial tension test data. Heat aging test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the rubber material and component test several useful life prediction equations for rubber component were proposed. Predicted useful life of rubber component for elevator cabin agreed fairly with the experimental lives.

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Characteristics Evaluation and Useful Life Prediction of Rubber Spring for Railway Vehicle (전동차용 방진고무스프링 특성평가 및 사용수명 예측)

  • Woo, Chang-Su;Park, Dong-Chul
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.104-111
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    • 2006
  • The non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by material tests which are uni-axial tension and bi-axial tension. The computer simulation using the nonlinear element analysis program executed to predict and evaluate the load capacity and stiffness for chevron spring. In order to investigate the heat-aging effects on the rubber material properties, the acceleration test were carried out. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful life prediction for rubber material were proposed.

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A Study on the Lifetime Prediction of Rubber Mount for Refrigerator Component (냉장고 압축기용 고무마운트 수명예측에 관한 연구)

  • Woo Chang-Su;Park Hyun-Sung
    • Journal of Applied Reliability
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    • v.6 no.2
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    • pp.135-150
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    • 2006
  • Rubber material properties and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. This paper discusses the failure mechanism and material tests were carried out to predict the useful lifetime of NBR and EPDM for compression motor, which is used in refrigerator component. The heat-aging process leads not only to mechanical properties change but also to chemical structure change so called degradation. In order to investigate the aging effects on the material properties, the accelerated test were carried out. The stress-strain curves were plotted from the results of the tensile test for virgin and heat-aged rubber specimens. The rubber specimens were heat-aged in an oven at the temperature ranging from $70^{\circ}C\;to\;100^{\circ}C$ for a period ranging from 1 to 180 days. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful lifetime prediction equations for rubber material were proposed.

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Useful Lifetime Prediction of Coupling Rubber Pad for Railway Vehicles (철도차량 완충기 패드용 고무소재 수명예측)

  • Woo, Chang-Su;Park, Hyun-Sung;Park, Dong-Chul
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.923-931
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    • 2008
  • Coupling rubber pad are important components in railway vehicles. It can be used for reduce shock, vibration and noise. Simple tension, equi-biaxial tension and pure shear test were performed to acquire the coefficient of rubber material which were Mooney-Rivlin and Ogden model. The finite element analysis was executed to evaluate the behavior of deformation and stress distribution by using the commercial finite element analysis code. Useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, useful life prediction of rubber pad for railway vehicle were experimentally investigated. Accelerated heat-aging test for rubber material were carried. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot.

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COIN형 리튬 폴리머전지의 충방전 특성

  • 박수길;박종은;손원근;이흥기;김상욱;이주성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.497-500
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    • 1997
  • Conducting polymer is new material in lithium secondary battery. conducting polymer has a lot of merit which is flexible and good handing so that this material is used battery system, solid polymer electrolytes airs used PEO(Polyethylene oxide) and PEO/PMMA branding material adding by liquid plasticizer or lithium salt polymer electrolyte which is added liquid plasticizer, lithium salt decreased the crystallity and thermal stability is over than 13$0^{\circ}C$. it is very useful tn apply lithium secondary battery system.

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Effects of Thermal Aging on Properties and Life-time Prediction of NBR and EPDM Vulcanizates (열 노화에 따른 NBR과 EPDM 가황물의 물성변화 및 노화수명 예측)

  • Woo, C.S.;Choi, S.S.
    • Elastomers and Composites
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    • v.40 no.2
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    • pp.119-127
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    • 2005
  • Material characteristics and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the material test and accelerated heat aging test were carried out to predict the useful life of NBR and EPDM rubber mount for a compression motor which is used in a refrigerator. In order to investigate the effects of heat-aging on the material properties, crosslink density, modulus at 100% strain, stress-strain curves were obtained from uniaxial and equi-biaxial tensile tests. The change of compression set were used for assessment of the useful life and the time to threshold value were plotted against the reciprocal of absolute temperature to give the Arrhenius plot. The useful life at variable temperatures are obtained in the Arrhenius relationship.

Determination of plastic concrete behavior at different strain rates to determine Cowper-Symonds constant for numerical modeling

  • Nateghi, Reza;Goshtasbi, Kamran;Nejati, Hamid Reza
    • Computers and Concrete
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    • v.26 no.3
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    • pp.227-237
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    • 2020
  • Strain rate investigations are needed to calibrate strain-rate-dependent material models and numerical codes. An appropriate material model, which considers the rate effects, need to be used for proper numerical modeling. The plastic concrete cut-off wall is a special underground structure that acts as a barrier to stop or reduce the groundwater flow. These structures might be subjected to different dynamic loads, especially earthquake. Deformability of a structure subjected to dynamic loads is a principal issue which need to be undertaken during the design phase of these structures. The characterization of plastic concrete behavior under different strain rates is essential for proper designing of cut-off walls subjected to dynamic loads. The Cowper-Symonds model, as one of the most commonly applied material models, complies well with the behavior of a plastic concretes in low to moderate strain rates and will be useful in explicit dynamics simulations. This paper aims to present the results of an experimental study on mechanical responses of one of the most useful types of plastic concrete and Cowper-Symonds constant determination procedures in a wide range of strain rate from 0.0005 to 107 (1/s). For this purpose, SHPB, uniaxial, and triaxial compression tests were done on plastic concrete samples. Based on the results of quasi-static and dynamic tests, the dynamic increase factors (DIF) of this material in different strain rates and stress state conditions were determined for calibration of the Cowper - Symonds material models.

Reliability Design Technology of Rubber Materials for Electronic Components (전자부품 고무소재 신뢰성 설계기술)

  • Woo, Chang-Su;Park, Hyun-Sung;Choi, Seong-Shin
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1734-1739
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    • 2007
  • The materials characteristics and lifetime evaluation are very important in design procedure to assure the safety and reliability of rubber components. This paper discusses the failure mechanism and material test were carried out to predict the useful life of NBR and EPDM rubber mount for compression motor which is used in refrigerator. In order to investigate the heat-aging effects on the materials properties, stress-strain curve were obtained from the results of material tests. Compression set results changes as the threshold are used for assessment of useful life and the time were plotted against reciprocal of absolute temperature to give the Arrhenius plot.

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Characteristics and Useful Life Prediction of Rubber Spring for Railway Vehicle (전동차용 방진고무스프링 특성 및 사용수명 예측)

  • Woo, Chang-Su;Park, Hyun-Sung;Park, Dong-Chul
    • Journal of the Korean Society for Railway
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    • v.10 no.2 s.39
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    • pp.211-216
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    • 2007
  • Rubber components are widely used in many application such as vibration isolators, damping, ride quality. Rubber spring is used in primary suspension system for railway vehicle. Characteristics and useful life prediction of rubber spring was very important in design procedure to assure the safety and reliability. Non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by physical tests which are uniaxial tension, equi-biaxial tension and pure shear test. The computer simulation was executed to predict and evaluate the load capacity and stiffness for rubber spring. In order to investigate the useful life, the acceleration test were carried out. Acceleration test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the acceleration test, several useful life prediction for rubber spring were proposed.

Evaluation of Characteristics and Useful Life of Rubber Spring for Railway Vehicle

  • Woo, Chang-Su;Park, Hyun-Sung;Park, Dong-Chul
    • International Journal of Railway
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    • v.1 no.3
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    • pp.122-127
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    • 2008
  • Rubber components are widely used in many application such as vibration isolators, damping, ride quality. Rubber spring is used in primary suspension system for railway vehicle. Characteristics and useful life prediction of rubber spring was very important in design procedure to assure the safety and reliability. Non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by physical tests which are uniaxial tension, equi-biaxial tension and pure shear test. The computer simulation was executed to predict and evaluate the load capacity and stiffness for rubber spring. In order to investigate the useful life, the acceleration test were carried out. Acceleration test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the acceleration test, several useful life prediction for rubber spring were proposed.

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